| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Sieczkow | city | Poland | 50.53 | 20.98 | 718 | 4060 | |
| Siedlce | city | Poland | 50.75 | 20.50 | 797 | 10543 | |
| Siedliska | city | Poland | 50.38 | 20.03 | 1154 | 9727 | |
| Siekierno | city | Poland | 50.98 | 20.95 | 1151 | 6275 | |
| Siekierno Podmielewiec | city | Poland | 50.98 | 20.93 | 1082 | 5988 | |
| Siekierno Podmiescie | city | Poland | 50.97 | 20.95 | 1000 | 6273 | |
| Siekierno Przedgrabie | city | Poland | 50.98 | 20.95 | 1151 | 6275 | |
| Sielec | city | Poland | 50.33 | 20.42 | 698 | 6360 | |
| Sielec | city | Poland | 50.53 | 20.13 | 918 | 4908 | |
| Sielec Szpilalny | city | Poland | 50.37 | 20.68 | 643 | 4675 | |
| Sielpia | city | Poland | 51.12 | 20.35 | 784 | 6569 | |
| Sielpia Duza | city | Poland | 51.12 | 20.35 | 784 | 6569 | |
| Sielpia Wielka | city | Poland | 51.12 | 20.35 | 784 | 6569 | |
| Siennica Różana | city | Poland | 51.00 | 21.32 | 702 | 11775 | |
| Sieradowice | city | Poland | 50.97 | 20.98 | 918 | 6846 | |
| Sieradowice Drugie | city | Poland | 50.97 | 20.97 | 951 | 6644 | |
| Sieradowice Pierwsze | city | Poland | 50.95 | 20.97 | 902 | 6688 | |
| Sieraków | city | Poland | 50.80 | 20.88 | 1108 | 4522 | |
| Sieroslawice | city | Poland | 51.20 | 20.37 | 879 | 16768 | |
| Sierosławice | city | Poland | 51.20 | 20.37 | 879 | 16768 | |
| Sierzawy | city | Poland | 50.95 | 21.03 | 984 | 8157 | |
| Sieslawice | city | Poland | 50.45 | 20.70 | 731 | 10710 | |
| Siesławice | city | Poland | 50.45 | 20.70 | 731 | 10710 | |
| Sietadowice | city | Poland | 50.97 | 20.98 | 918 | 6846 | |
| Sieńsko | city | Poland | 50.63 | 20.05 | 1000 | 4361 | |
| Sitkówka | city | Poland | 50.82 | 20.57 | 866 | 88921 | |
| Sitkówka-Nowiny | city | Poland | 50.82 | 20.57 | 866 | 88921 |